/*
 * @Author: C.
 * @Date: 2021-06-11 09:39:51
 * @LastEditTime: 2021-07-20 13:46:52
 * @Description: file content
 */
const dialogDrag =
  {
    bind(el, binding, vnode, oldVnode) {
      const dialogHeaderEl = el.querySelector('.el-dialog__header')
      const dragDom = el.querySelector('.el-dialog')
      dialogHeaderEl.style.cursor = 'move'

      // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
      const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null)

      dialogHeaderEl.onmousedown = (e) => {
        // 鼠标按下，计算当前元素距离可视区的距离
        const disX = e.clientX - dialogHeaderEl.offsetLeft
        const disY = e.clientY - dialogHeaderEl.offsetTop
        const screenWidth = document.body.clientWidth // body当前宽度
        const screenHeight = document.documentElement.clientHeight // 可见区域高度(应为body高度，可某些环境下无法获取)
        const dragDomWidth = dragDom.offsetWidth // 对话框宽度
        const dragDomheight = dragDom.offsetHeight // 对话框高度
        const minDragDomLeft = dragDom.offsetLeft
        const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth
        const minDragDomTop = dragDom.offsetTop
        const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight

        // 获取到的值带px 正则匹配替换
        let styL, styT

        // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
        if (sty.left.includes('%')) {
          styL = +document.body.clientWidth * (+sty.left.replace(/\%/g, '') / 100)
          styT = +document.body.clientHeight * (+sty.top.replace(/\%/g, '') / 100)
        } else {
          styL = +sty.left.replace(/\px/g, '')
          styT = +sty.top.replace(/\px/g, '')
        }

        document.onmousemove = function(e) {
          // 获取body的页面可视宽高
          // var clientHeight = document.documentElement.clientHeight || document.body.clientHeight
          // var clientWidth = document.documentElement.clientWidth || document.body.clientWidth

          // 通过事件委托，计算移动的距离
          var l = e.clientX - disX
          var t = e.clientY - disY

          // 边界处理
          if (-l > minDragDomLeft) {
            l = -minDragDomLeft
          } else if (l > maxDragDomLeft) {
            l = maxDragDomLeft
          }
          if (-t > minDragDomTop) {
            t = -minDragDomTop
          } else if (t > maxDragDomTop) {
            t = maxDragDomTop
          }
          // 移动当前元素
          dragDom.style.left = `${l + styL}px`
          dragDom.style.top = `${t + styT}px`

          // 将此时的位置传出去
          // binding.value({x:e.pageX,y:e.pageY})
        }

        document.onmouseup = function(e) {
          document.onmousemove = null
          document.onmouseup = null
        }
      }
    }
  }
export {
  dialogDrag
}
